Illness-related microbial pathogens typically gain access to a subject's body by way of the eyes, ears, nose, and mouth and are usually transmitted to these orifices by the hands. Therefore, sanitization of the hands and other skin which may come into contact with the eyes, ears, nose, and mouth can be an effective means to prevent the transmission of microbial pathogens and, in turn, prevent illness.
Several hand sanitizers are currently marketed. For example, Purell® Instant Hand Sanitizer is a “gelled alcohol” hand sanitizer. The Purell® product uses ethyl alcohol as the active ingredient, in a formulation with a polymer thickener to allow for ease of use. Alcohol-based skin sanitizers suffer a few significant drawbacks. First, alcohol tends to dry and irritate the skin. Second, alcohol is flammable and requires special handling and storage procedures during manufacture and formulation. Finally, alcohol has no residual efficacy. Thus, although the alcohol-based sanitizers may kill pathogenic microbes on contact, after the alcohol evaporates, there is no means for control of microbial growth.
Gelled alcohol sanitizers suffer from the further drawback that the polymer thickeners trap dead skin and bacteria cells on the surface of the skin.
Quaternary ammonium compounds, such as benzalkonium chloride, possess antimicrobial activity against a wide range of microbial pathogens, including bacteria, fungi, and viruses. Quaternary ammonium compounds have advantages over alcohol-based products. First, although quaternary ammonium compounds are broadly effective antimicrobials, these compounds demonstrate relatively low toxicity to animals. Second, quaternary ammonium compounds are essentially odorless, making them easy to formulate in personal care products Finally, quaternary ammonium compounds do not degrade or corrode materials, such as steel, plastics, and rubber.
Disinfectant compositions containing the quaternary ammonium compound, benzalkonium chloride are known, however, these compositions are generally liquid or contain polymers or surfactants which result in an unpleasant feel, such as tackiness and stickiness, on the skin following application.
Thus, there is a need for a highly effective antimicrobial composition in a format convenient for no-rinse application to the skin, which dries quickly, leaves the skin smooth, comfortable, and adequately moisturized.